Lock-stitch sewing machine



3EST AVAILABLE COP" Nov. 2 1926. A. B. FOWLER LOCKSTI'I'CH sswme MACHINE Filed Dec. '7, 1922 3 Sheets-Sheet l Nov. 2, 1926.

BEST AVAILABLE cop 1,605,431 A. B. FOWLER LOCKSTITCH SEWING MACHINE 3 Sheets-Sheet 2 Filed Dc. '2, 1922 BEST AVAlLABLE COP Nov. 2,1926. 1,605,431

A. B. FOWLER LOCKST'ITCH SEWING MACHINE Filed Dad. 7, 1922 3 Sheets-Sheet 5 5? 6 7 I0 BEST AVAiLABLE Patented Nov. 2, 1926.

NI-Ten STATES 1,605,431 PATENT OFFICE,

, ALFRED B..- FowLER', or BEVERLY, MASSACHUSETTS, ASSIGNOR To UNITED SHOE meonmnarconronn'rron, or PATERSON, NEW JERSEY, A oonronn'rlonor I .NEw ERsEY,

LOCK-STITCH SEWING MACHINE.

' The present invention relates to lockstitch sewing machines, the stitch forming devices of which-include a hook needle by which 'loops'of-nee dle thread are drawn through the' work and a loop taker in the form of a shut-tleor hook for passing a'locking thread through the needleloops, which loop taker is necessarily located on the same side of the Work'a's the hook needle. More particularly the"invention relates'to that class of hook needle-lockstitch sewing machines which are not provided with a thread arm or other device to measure off between the needle and the workasuificient amount of thread to supply one side of the needle loop as the needle retracts through the work after the thread has been laid in its hook. An exaniple :of thisclass of machines is the socalled lockstitch McKay sewing machine in which the shoe is supported during the sewing operation by a horn which extends inside of the shoe and which sews a seam passing through the shoe sole from the outside to the inside of the shoe. In machines of this type it has been found to be impracticable to use a thread arm or thread measuring device of any kind to supply thread for one side of the needle loop and, accordingly, where these machines have been provided with a take-up to set the stitch it has been necessary to use an extremely large needle as compared with the size of the thread in order to permit the thread to 5 reeve through the hook of the needle during its retraction through the work. To avoid the use of a large needle in these machines, the shuttle has been untilized to set the stitch, and whether or not a take-up is embodied-in. the machine, at least a portion of theneedle loop after being passed around the shuttle has been left projecting from the work so that the needle during its retracting stroke can be supplied with thread from this loop. lVith these machines in order to produce a satisfactory seam in the Work on which they are designed to operate it is necessary to set the stitch against a thread lock and; in a machine in which the stitch is set by the shuttle it has heretofore been necessary to open the lock during'the action of the shuttle in setting the stitch so as to permit the shuttle to pull off thread from the supply for the next stitch. With this mode of operation irregularities in the posi-' Application filed December 7, 1922. Serial No. 605,383.

tion of the lock of the stitch in the work are bound to occur and also there is liability of injury to the thread as it is-drawn through the look at the instant the lock is opened;

The object of the present invention is to eliminate the defects in the construction and operation of prior hook needle lockstitch ma chines which are not provided with'a' thread arm or other'thread v measuring device to supply thread for one side of the needle loop and to provide a machine of this class which will operate to set the locks of the-'stitches accurately in the-work without-liabilityiof breaking or injuring the 'thread,'-andwith this object in view the present invention contemplates the provision, in a'machine'ofthis class, of a thread handling deviceyvhich cooperates with the other thread handling devices of the machine in-such a manneras to permit the thread lock against 'which the stitch is set tobe opened and closed at points in the cycle of operation when the device which is used to set'the stitch is-not exerting a strain on the thread tending to pull the thread through the thread lock. By the provision of such a thread'handling device the various parts which are utilized in forming and setting the stitch can-be constructed and arranged to operate insuch a manner that one of saidparts acts to' set the stitch and another of said parts acts'to" draw thread from the supply for the next stitch. The operations of setting'the stitch and of drawing thread from the supply for the next stitch being thus separated the thread can be manipulated with extremeaccuracy, so that the lock of the stitch will always be drawn to the same location with relation to the surface of the work and at the same time the use of a small needle is permitted and liability of injury to the thread is eliminated.

In its broader aspects the invention contemplates the provision of any form of thread handling device which will cooperate with the other parts'to permit the desired mode of operationand contemplates utilizing any suitable parts for the setting of the stitch and for drawing thread from the supply for the next stitch. It is preferred, however, to use the shuttle to set the stitch, it being noted that the term shuttle as here used and as hereafter used in the claims is intended to include a hook or other BEST AVAlLABLE coP 2 trolled by the thickness of the workfor varying the action of-the pull-off. Also in order to eliminate as far as possible the reevingof' thethread around the materials being sewed the machine aisi preferably provided with a take-up I acting to pi'illwthe-n'eedle iloop rfrom the .shnttlezpartially back through the 1 worlr.

The! preferred :form of the present ,invention is illustrated in: the: accompanying drawings :asembodied :ina lockstitch {Mc- Kay ishoe g; machine, so muchonly of the "machine {being-g illustrated asis -'nece'ss'aryxfor :a-n understanding of the present invention. gFlgurei :1 :iS': ay-view' rin -side"elevationof'theimachinefxFigure 12 is a'i'detail view n-s'howing in ifrbnl: elevation and :par-

tiallyin section: certain parts of the. machine and ipart-icularly the r'pull-ofi mechanism 2 and its connection with .the presser 'ioot Figure 3:i'sadetait sectional-. plan-view :off the pullofi' mechanism an'd thread locks cFigureF' is I a View in sideelevatiomn partlyin section, of :the ;mechanism :illustrated zin-Fig'ure '3; Figure 5 is asdtail viewinsideelev-ation of the lfnechanism-sfor actuating the thread 1ocks;;andFigu'res':6, 7-and-8 are diagrammatic views illustrating the operation-of the thread ihandling devices of the machine in forming :andr'settinga stitch.

'vExcept-as hereinafter-described the machine-illustrated in 'the drawings is the same in "construction andmode of operation as the lockstitchfMcKay: shoe sewing machine illustrated and'described: infthepatent'to Goddard and Jerram;lid-1 3535827, dated September 28, .1920. 1 Referring to Figures 1 and 2,--the straight hook needle 'of the machine is indicated at 9'5'the shuttleat 10,:the=1')resser;foot at 11,.tll6'f86d point at 12, theshoe-supportinghorn at 13, and thewhirl which laysiihe thread inthehook of; the necdle' at 14: The

needle, presser foot and fee'd'poin't are -a'ctuated from a horizontal camshaft "driven through='ibevelled-gears 15"and '16 frdm a vertical shatt'l'l' and the shuttle-and Whirl are driventhrough connections from the vertical'shatt 17,- as in'the'-=machine "of-the Goddardiand Jerram patent." I

The "illustrated machine is :provided with a thread flock against vwhich the stitch is set'by the shuttle, which look corresponds to the threadlock of the machin'e'of' the God- (lard and Jerram patent. T 0 permit this lock to be opened and closed at times in"'the cycle when the re.--is nostrain on the; thread tending :to 'pull itithroiigli'. theZ-lock; the il- -lustratedmachine is provided with a second thread lock ,located between t the first menlock to pull off from the supplythe "amountof thread needed in the formation of a stitch. The thread lock against which the stitch is --=setcomprises two members consisting respectively of a spring pressed plunger 18 mounted upon a --lever 19 (and: a fix'ed clamping plate 20 mounted :upon a,bracket' -2l.-secured to the frame ?of the wmachine.-- {Bhis thread lock may be-termed thewrfearithreadzlockPi The other thread lock which may: be {termed the :f'rontthread lodkQ-cbmpri'ses two members consisting of 1a spring pressed vrpl-unger 2- 7 mounted 'in the zlever eltlawa'nd l ia vfixed clamping-platez23 mounted zirhthe bracket; 21.

The lever 194s ;pivo.tally= mounted :midEWay between the plungers '18 amd-=i22dupbn1the bracket 21 and is :pro'v-idediwith an arm;ha:ving a pin {and slot engaigement witlmthe riorward end of alever 2:4;itl1- rear filldfOf' which is engaged 'by a :cam' rgroove lll'tthe :barrel member. 25 on 'the vertical shaft-:17. With this construction, 'as the ilever e19 sis irooked, one of the thread- 'clampsz is opened and the other closed. 'The u11-.-ofi device 'is. located between the two thread clatnpsiarfldk'comprises a fork 26 acrosswhich-ithe' thread extends as it passes fromsthevs'upply through the two threa'd-blamps, and a rpulleofiarm 27 the end'of which extends 'o'ver therthreadabove thertv'voarmseoit theifork 26 andwhith, as the e'ndoff-the arm is moved downwardly, is adapted to bendathe thread downwalfdlyzbetween thetwo armsofthelfo'rk. Yillhe arm 27 :forms part -i of -:a lever, 1 the rear end i of which is engaged obylacamain' the-i liarre'l member- 25. To cause-ethe pull-ofi I device-to pull off auamount-Fof thread varyingww ith.

the thickness ofthe --work the -:-fork 126 '{iS formed at the upper endof 'a verticalu-ba-r 28 mounted to slide in the-bracket :21-;and connected'to' the resser ztootrcarrying bar of the machine by a lever 29-, vertical connecting rod -80'.and 'a Plever 31. "An adjustable bolt and slot connection betweentthefconnecting rod 30-and theilever'f29 permitsvan adj ustment of the parts to "cause the desired variation in theamd-unt of:thread' pulled"off upon a variation in the thickness of the work.

In addition to 'thelthreadhandling pants above described the :illustratedwinachine is also provided with cam? actuated take-up .levers 32' and 33 carryih gtake-up rolls '34aa-nd 35 which are arranged to operate in substantially the 1 same :mannerfas :th'e take-up levers 0t the'machine of the Goddardandflerram n V l l in ion llt'

and setting a stitch is as follows :-Starting with the needle at the limit of its upward stroke the needle descends through the work so as to bring its hook into position to receive the thread which is laid therein by the whirl in the tip of the horn. At this time in the cycle the parts are in substantially the position indicated in Figure 6, the take-up levers being separated to their greatest extent, the front thread lock being closed and the rear thread lock being opened. At this point in the operation it will be noted that the loop of needle thread which has just been passed around the shuttle has been pulled a only partially back through the work.

After receiving the thread in its hook the needle retracts to the position indicated in Figure 7 and during this movement thread for the work side of the loop drawn up by the needle is supplied from the preceding loop so that there is no rendering of the thread through the hook of the needle and the needle can pass through the work without any danger of breaking the thread. During the upward movement of the needle, thread for the supply side of the loop is given up by the take-up levers which approach each other. At some point in the cycle of operation while the front thread lock remains closed the pull-off is actuated to pull thread from the supply through the rear thread lock, as indicated in Figure 6. As the needle nears the limit of its upward stroke the loop is engaged by the shuttle and extended to the position indicated in Figure 8, and prior to the time when the parts reach this point in the cycle the front thread lock is opened and the rear thread lock is closed so that the thread which has been pulled oil by the take-up is permitted to pass through the front thread lock and the thread is drawn tight between the top of the shuttle and the rear thread lock. The amount of thread which has been drawn off by the takeup is just suflicient to cause a stitch setting strain to be exerted upon the thread as the loop of needle thread passes over the top of the shuttle so as to set the lock of the stitch in the required position with relation to the surface of the work. After the stitch is set the take-up is actuated to draw the loop from the shuttle partially back through the work to the position indicated in Figure 6, and at some time after the thread is relieved of the stitch setting pull of the shuttle the rear thread lock is opened and the front thread lock is closed.

The nature and scope of the present in- BEST AVAILABLE COP:

vention having been indicated and the preferred embodiment of the invention having been specifically described, what is claimed 1s:

1. A lockstitch sewing machine having, in combination, stitch forming and setting devices including a hook needle operating during its retraction to draw thread from the preceding needle loop, a shuttle, a thread lock against which the stitch is set, and a thread handling device cooperating with said needle, shuttle and thread lock to permit the thread lock to be opened and closed while the thread is relieved of strain tending to pull it through the lock.

2. A lockstitch sewing machine having, in combination, stitch forming and setting devices including a hook needle, a shuttle acting to set the stitch, a thread lock against which the stitch is set, a pull-off, and means for varying the action of the pull-oft to compensate for different thicknesses of work.

3. A lockstitch sewing machine having, in combination, stitch forming and setting de vices including a hook needle, a take-up acting to pull the needle loop from the shuttle partially back through the work, a shuttle acting to set the stitch, a thread lock against which the stitch'is set, a pull-off, and means for varying the action of the pull; off to compensate for different thicknesses of work.

4. A lockstitch sewing machine having, in combination, stitch forming and setting devices including a hook needle operating during its retraction to draw thread from the preceding needle loop, a shuttle, a thread lock against which the stitch is set, a pulloff, and means for Varying the action of the pull-off to compensate for difierent thicknesses of work.

5. A lockstitch sewing machine having, in combination, stitch forming and setting de vices including a hook needle operating during itsretraction to draw thread from the preceding needle loop, a shuttle, a thread lock against which the stitch is set, a thread handling device cooperating with said needle, shuttle and thread lock to permit the thread lock to be opened and closed while the thread is relieved of strain tending to pull it through the lock, and means for actuating the needle, shuttle, thread lock and thread handling device to cause one of said parts to set the stitch and another of said parts to draw thread from the supply.

ALFRED B. FOWLER. 

